CODEWITHSUNDEEP
swiftswiftui
Nouman
Nouman

Reputation: 670

Type () cannot conform to View; only struct/enum/class types can conform to protocols

I am following this tutorial https://www.youtube.com/watch?v=Xd0J18isFEQ for my app which is a simple app that shows a list of values on the homescreen + then has a detail view for each row

I have implemented a router to dictate the routing for my app as below:

enum Router {
    case detail(Result)
}

struct Navigator {
    static func navigate<T: View>(_ route: Router, content: () -> T) -> AnyView {
        switch route {
        
        case .detail(let item):
            return AnyView(NavigationLink(
                            destination: DetailView(story: item)) {
                            content()
                
            })
        }
    }
}

And I am using it on my homescreen embedded like this:

struct Home: View {
    @ObservedObject var newsfeed = Newsfeed()
    @State var page: Int = 1

    var body: some View {
        List {
            ForEach(newsfeed.data) { item in
                
                Navigator.navigate(.detail(item)) {
                    HStack {
                        WebImage(url: URL(string: item.fields.thumbnail)!)
                            .resizable()
                            .scaledToFill()
                            .frame(width: 120, height: 120)
                            .cornerRadius(2)
                    }
                    VStack (alignment: .leading, spacing: 5) {
                        Text(item.fields.headline)
                            .font(.headline)
                            .fontWeight(.bold)
                        Text(item.fields.trailText)
                            .font(.caption)
                    }
                    .frame(maxHeight: 120)
                }
                .onAppear() {
                    if (newsfeed.data.last == item) {
                        newsfeed.loadData(pageParam: page + 1, search: nil, key: nil) { result, size in
                            if (result != nil) { newsfeed.data.append(contentsOf: result!) }
                            if (size != nil) { newsfeed.pageSize += size! }
                        }
                        self.page += 1
                    }
                }
            }
        }
    }
}

But I am getting an error on Navigator.navigat.. Type '()' cannot conform to View, only struct/enum/class types can conform to protocols

Upvotes: 0

Views: 278

Answers (1)

jnpdx
jnpdx

Reputation: 52337

navigate, as written, wants to take one argument, but you're sending it both an HStack and a VStack.

@ViewBuilder can solve this for you, which is an annotation (used often in SwiftUI, especially in the built-in components) that lets the view have/return multiple root-level elements:

static func navigate<T: View>(_ route: Router, @ViewBuilder content: () -> T) -> AnyView {

Upvotes: 2

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